1236057 MEK mitogen-activated protein kinase kinase 1430 2353181 MAPKK mitogen-activated protein kinase kinase 142 1254191 MKK mitogen-activated protein kinase kinase 64 2201629 MAPKKs mitogen-activated protein kinase kinases 28 3051558 MKKs mitogen-activated protein kinase kinases 18 3032778 MEKs mitogen-activated protein kinase kinases 9